Technical Key Points of Lotus Root Field Rotation and Crop Succession Cultivation Models

Lotus root is an important aquatic vegetable in China and also an important export-oriented vegetable for earning foreign exchange. It is widely cultivated in areas south of the Huang-Huai region, especially in the Yangtze River Basin and areas further south. It not only plays an important role in increasing farmers' income and improving agricultural efficiency, but also has important value in improving and beautifying the environment, and in wetland protection and utilization. Centering on lotus root and carrying out good rotation and crop succession is of great significance for fully improving land utilization rate and economic benefits per unit area, reducing disease and pest damage, reducing pesticide use, improving soil and enhancing soil fertility.

1. Characteristics of lotus root fields. Lotus root has a relatively strong tolerance for continuous cropping. In actual production, the vast majority of lotus root fields are continuously cropped for many years. Under normal circumstances, in the same field, lotus root can be used as the center for crop succession arrangement for several consecutive years. When lotus root is cultivated in the open field in the Yangtze River Basin region, it is generally planted from mid-to-late March to early-to-mid April, green lotus roots are harvested from July to August, and mature lotus roots begin to be harvested from September to October; for early-maturing cultivation under plastic large (medium) tunnel covering, it is planted around mid-March, green lotus roots are harvested from June to July, and mature lotus roots begin to be harvested from August to September. Whether in open-field cultivation or protected cultivation, when the goal is to harvest green lotus roots, the field can mostly be cleared in July; if the goal is to harvest mature lotus roots, harvesting can begin from mid-to-late August and continue until the end of April the following year. As long as the lotus root harvesting period is reasonably arranged, there is relatively great flexibility in arranging crop succession in lotus root fields.

2. Lotus root field crop succession models. (1) Lotus root - late rice - upland vegetable

First crop: lotus root. In this model, lotus root adopts early-maturing cultivation techniques, including selecting early-maturing varieties (such as E-lian No. 1, Xin No. 1 lotus root, etc.), increasing the amount of planting material used, increasing density, planting early, using protected facilities, and harvesting and marketing in a timely manner. Generally, green lotus roots are completely harvested in early-to-mid July, with a yield (yield per 667 sq m, the same below) of 750 kg.

Second crop: late rice. Late rice is transplanted in mid-to-late July and harvested in mid-to-late October, with a yield of 450 kg.

Third crop: upland vegetable. After the late rice is harvested, one season of upland vegetable is planted. The period from field sowing or transplanting of upland vegetables to the completion of harvest should preferably be from late October to early-to-mid April of the following year, on the premise that it does not affect lotus root planting in the second year. Suitable upland vegetable types include spring radish, pak choi, red flowering stalk, late-maturing cauliflower, spring lettuce, celery, spinach, potherb mustard, etc. Spring radish can be sown from November to early January of the following year and harvested from January to April, with a yield of 2000 kg; pak choi can be directly sown or transplanted from late October to January of the following year and harvested from November to April of the following year, with a yield of 1500 kg; red flowering stalk is transplanted in late October and begins to be harvested in late February of the following year, with a yield of 1200 kg; cauliflower is transplanted from late October to November and harvested from late March to early-to-mid April, with a yield of 1500 kg; spring lettuce is transplanted in November and harvested from late March to early-to-mid April, with a yield of 2500 kg; celery is transplanted from late October to early November and harvested before early-to-mid April, with a yield of 2000 kg; spinach is directly sown from late October to November of the following year and harvested from December to March of the following year, with a yield of 2000 kg; potherb mustard is transplanted from late October to November and harvested in March of the following year, with a yield of 2000 kg.